Background
Tuberculosis
(TB), a multisystemic disease with myriad presentations and
manifestations, is the most common cause of infectious disease–related
mortality worldwide. The World Health Organization (WHO) has estimated
that 2 billion people have latent TB and that globally, in 2009, the
disease killed 1.7 million people.[1] New TB treatments are being developed,[2] and new TB vaccines are under investigation. (See Epidemiology and Treatment and Management, below.)[3]